Rina Su

Alteration in Expression and Methylation of IGF2/H19 in Placenta and Umbilical Cord Blood Are Associated with Macrosomia Exposed to Intrauterine Hyperglycemia

Objective Macrosomia is one of the most common complications in gestational diabetes mellitus. Insulin-like growth factor 2 and H19 are two of the imprinted candidate genes that are involved in fetal growth and development. Change in methylation at differentially methylated region of the insulin-like growth factor 2 and H19 has been proved to be an early event related to the programming of metabolic profile, including macrosomia and small for gestational age in offspring. Here we hypothesize that alteration in methylation at differentially methylated region of the insulin-like growth factor 2 and H19 is associated with macrosomia induced by intrauterine hyperglycemia. Results The expression of insulin-like growth factor 2 is significant higher in gestational diabetes mellitus group (GDM group) compared to normal glucose tolerance group (NGT group) both in umbilical cord blood and placenta, while the expression of H19 is significant lower in GDM group in umbilical cord blood. The expression of insulin-like growth factor 2 is significant higher in normal glucose tolerance with macrosomia group (NGT-M) compared to normal glucose tolerance with normal birthweight group (NGT-NBW group) both in placenta and umbilical cord blood. A model with interaction term of gene expression of IGF2 and H19 found that IGF2 and the joint action of IGF2 and H19 in placenta showed significantly relationship with GDM/NGT and GDM-NBW/NGT-NBW. A borderline significant association was seen among IGF2 and H19 in cord blood and GDM-M/NGT-M. The methylation level at different CpG sites of insulin-like growth factor 2 and H19 in umbilical cord blood was also significantly different among groups. Based on the multivariable linear regression analysis, the methylation of the insulin-like growth factor 2 / H19 is closely related to birth weight and intrauterine hyperglycemia. Conclusions We confirmed the existence of alteration in DNA methylation in umbilical cord blood exposed to intrauterine hyperglycemia and reported a functional role in regulating gene associated with insulin-like growth factor 2/H19. Both of these might be the underlying pathogenesis of macrosomia. We also provided the evidence of strong associations between methylation of insulin-like growth factor 2/H19 and macrosomia induced by intrauterine hyperglycemia.

Long-Term Effects of Maternal Diabetes on Blood Pressure and Renal Function in Rat Male Offspring

Aims/Hypothesis Gestational diabetes mellitus (GDM) is increasing rapidly worldwide. Previous animal models were established to study consequences of offspring after exposure to severe intrauterine hyperglycemia. In this study we are aiming to characterize the blood pressure levels and renal function of male offspring obtained from diabetic mothers with moderate hyperglycemia. Methods We established a rat model with moderate hyperglycemia after pregnancy by a single intraperitoneal injection of streptozotocin (STZ). The male offspring were studied and fed with either normal diet or high salt diet after weaning. Arterial pressure and renal function were measured. Results Arterial pressure of male offspring increased from 12 weeks by exposure to intrauterine moderate hyperglycemia. At 20 weeks, high salt diet accelerated the blood pressure on diabetic offspring compared to diabetic offspring fed with normal diet. We found offspring exposed to intrauterine moderate hyperglycemia had a trend to have a higher creatinine clearance rate and significant increase of urinary N-acetyl-β-D-glucosaminidase (NAG) excretion indicating an early stage of nephropathy progression. Conclusions/Interpretation We observed the high blood pressure level and early renal dysfunction of male offspring obtained from diabetic mothers with moderate hyperglycemia. Furthermore, we investigated high salt diet after weaning on offspring exposed to intrauterine hyperglycemia could exacerbate the blood pressure and renal function. Renin angiotensin system (RAS) plays an important role in hypertension pathogenesis and altered gene expression of RAS components in offspring with in utero hyperglycemia exposure may account for the programmed hypertension. Therefore, our study provides evidence “fetal programming” of maternal diabetes is critical for metabolic disease development.

The Predictive Effects of Early Pregnancy Lipid Profiles and Fasting Glucose on the Risk of Gestational Diabetes Mellitus Stratified by Body Mass Index.

This study aimed at evaluating the predictive effects of early pregnancy lipid profiles and fasting glucose on the risk of gestational diabetes mellitus (GDM) in patients stratified by prepregnancy body mass index (p-BMI) and to determine the optimal cut-off values of each indicator for different p-BMI ranges. A retrospective system cluster sampling survey was conducted in Beijing during 2013 and a total of 5,265 singleton pregnancies without prepregnancy diabetes were included. The information for each participant was collected individually using questionnaires and medical records. Logistic regression analysis and receiver operator characteristics analysis were used in the analysis. Outcomes showed that potential markers for the prediction of GDM include early pregnancy lipid profiles (cholesterol, triacylglycerols, low-density lipoprotein cholesterol/high-density lipoprotein cholesterol ratios [LDL-C/HDL-C], and triglyceride to high-density lipoprotein cholesterol ratios [TG/HDL-C]) and fasting glucose, of which fasting glucose level was the most accurate indicator. Furthermore, the predictive effects and cut-off values for these factors varied according to p-BMI. Thus, p-BMI should be a consideration for the risk assessment of pregnant patients for GDM development.

Positive Correlation between Enhanced Expression of TLR4/MyD88/NF-κB with Insulin Resistance in Placentae of Gestational Diabetes Mellitus.

Insulin resistance (IR) is a critical factor of the pathophysiology of Gestational diabetes mellitus (GDM). Studies on key organs involved in IR, such as livers and adipose tissues, showed that Toll-like receptor 4 (TLR4) can regulate insulin sensitivity. As a maternal-fetal interface with multi-functions, placentae could contribute to the development of IR for GDM. Thus, we investigated the expressions of TLR4/Myeloid Differentiation factor 88 (MyD88)/Nuclear Factor kappa-light-chain-enhancer of activated B cells (NF-kB) in term placentae from 33 GDM women and 36 healthy pregnant women with normal glucose tolerance, evaluated local and systemic IR and furthermore identified the association between placental TLR4 and IR. TLR4 protein was expressed in various cells of term placenta, particularly in syncytiotrophoblast of villi. Compared with normal pregnancy, the expression of TLR4/MyD88/NF-kB pathway increased in the placenta of GDM (p<0.05), and these differences were more pronounced in the maternal section of the placenta and the syncytiotrophoblast of villi. In addition, more severe IR was observed in the placenta of GDM patients than the control group, evidenced with higher pIRS-1(ser312) (p<0.001) and lower IRS-1 (p<0.05) as well as pAkt proteins (p<0.01). The expression of TLR4 in placentae is positively correlated with local IR (pIRS-1: r = 0.76, p <0.001 and pAkt: r = -0.47, p <0.001) and maternal fasting (r = 0.42, p <0.01), one-hour (r = 0.52, p <0.01) and two-hour glucose (r = 0.54, p <0.01) at OGTT. We found an that enhanced expression of the TLR4-MyD88-NF-kB pathway occurs in GDM placentae, which positively correlates with heightened local IR in placentae and higher maternal hyperglycemia. The TLR4/MyD88/NF-kB pathway may play a potential role in the development of IR in placentae of GDM.

High Prevalence of Gestational Diabetes Mellitus in Beijing: Effect of Maternal Birth Weight and Other Risk Factors

Background: Gestational diabetes mellitus (GDM) is associated with both short- and long-term adverse health consequences for both the mother and her offspring. The aim was to study the prevalence and risk factors for GDM in Beijing. Methods: The study population consisted of 15,194 pregnant women attending prenatal care in 15 hospitals in Beijing, who delivered between June 20, 2013, and November 30, 2013, after 28 weeks of gestation. The participants were selected by cluster sampling from the 15 hospitals identified through random systematic sampling based on the number of deliveries in 2012. A questionnaire was designed to collect information. Results: A total of 2987 (19.7%) women were diagnosed with GDM and 208 (1.4%) had diabetes in pregnancy (DIP). Age (OR: 1.053, 95% CI: 1.033–1.074, P < 0.01), family history of diabetes mellitus (OR: 1.481, 95% CI: 1.254–1.748, P < 0.01), prepregnancy body mass index (BMI) (OR: 1.481, 95% CI: 1.254–1.748, P < 0.01), BMI gain before 24 weeks (OR: 1.126, 95% CI: 1.075–1.800, P < 0.01), maternal birth weight (P < 0.01), and fasting plasma glucose at the first prenatal visit (P < 0.01) were identified as risk factors for GDM. In women with birth weight <3000 g, GDM rate was significantly higher. Conclusions: One out of every five pregnant women in Beijing either had GDM or DIP and this constitutes a huge health burden for health services. Prepregnancy BMI and weight gain before 24th week are important modifiable risk factors for GDM. Ensuring birth weight above 3000 g may help reduce risk for future GDM among female offsprings.

Transgenerational Glucose Intolerance of Tumor Necrosis Factor with Epigenetic Alteration in Rat Perirenal Adipose Tissue Induced by Intrauterine Hyperglycemia.

Changes in DNA methylation may play a role in the genetic mechanism underlying glucose intolerance in the offspring of mothers with diabetes. Here, we established a rat model of moderate intrauterine hyperglycemia induced by streptozotocin to detect glucose and lipid metabolism of first-generation (F1) and second-generation (F2) offspring. Moderate intrauterine hyperglycemia induced high body weight in F1 and F2 offspring of diabetic mothers. F1 offspring had impaired glucose tolerance and abnormal insulin level. Additionally, F1 and F2 offspring that were exposed to intrauterine hyperglycemia had impaired insulin secretion from the islets. The tumor necrosis factor (Tnf) gene was upregulated in perirenal adipose tissue from F1 offspring and relatively increased in F2 offspring. Both F1 and F2 offspring showed similar hypomethylation level at the −1952 site of Tnf. We confirmed that DNA methylation occurs in offspring exposed to intrauterine hyperglycemia and that the DNA methylation is intergenerational and inherited.

Genetic Variants and Clinical Relevance Associated with Gestational Diabetes Mellitus in Chinese Women: a Case-Control Study

Abstract Purpose: Gestational diabetes mellitus (GDM) may share similar mechanisms with type 2 diabetes and obesity. In the current study, we aimed to verify twenty genes reported to be associated with type 2 diabetes and obesity in the Chinese GDM population. Methods: Pregnant women aged 20–49 years at 24–28 gestational weeks were recruited and 556 cases and 445 controls were enrolled in the study. The genotyping of single nucleotide polymorphisms (SNPs) was performed on peripheral blood samples. Results: We discovered that GDM was associated with rs945508 (OR = 1.368, 95% CI = 1.080–1.732, p = .009), rs10804591 (OR = 1.446, 95% CI = 1.192–1.754, p < .001), rs10245353 (OR = 1.204, 95% CI = 1.006–1.441, p = .043) and rs1552224 (OR = 1.451, 95% CI = 1.071–1.964, p = .016). Conclusions: We found that four SNPs associated with type 2 diabetes and obesity may also increase the risk of developing GDM in the Chinese population. Among these SNPs, we report for the first time that rs945508 in ARHGEF11, rs10804591 in PLXND1 and rs10245353 in NFE2L3 were associated with GDM.

Relationship between Oral Glucose Tolerance Test Characteristics and Adverse Pregnancy Outcomes among Women with Gestational Diabetes Mellitus

Background: Hyperglycemia is associated with adverse pregnancy outcomes. However, the relationships between them remain ambiguous. This study aimed to analyze the effect of different oral glucose tolerance test (OGTT) results on adverse perinatal outcomes. Methods: This retrospective cohort study included data from 15 hospitals in Beijing from June 20, 2013 to November 30, 2013. Women with gestational diabetes mellitus (GDM) were categorized according to the number and distribution of abnormal OGTT values, and the characteristics of adverse pregnancy outcomes were evaluated. Chi-square test and logistic regression analysis were used to determine the associations. Results: In total, 14,741 pregnant women were included in the study population, 2927 (19.86%) of whom had GDM. As the number of hyperglycemic values in the OGTT increased, the risk of cesarean delivery, preterm births, large-for-gestational age (LGA), macrosomia, and neonatal complications significantly increased. Fasting hyperglycemia had clear associations with macrosomia (odds ratios [ORs]:1.84, 95% confidence intervals [CIs]: 1.39–2.42, P < 0.001), LGA (OR: 1.70, 95% CI: 1.29–2.25, P < 0.001), and cesarean delivery (OR: 1.33, 95% CI: 1.15–1.55, P < 0.001). The associations were stronger as fasting glucose increased. GDM diagnosed by hyperglycemia at OGTT-2 h was more likely to lead to preterm birth (OR: 1.50, 95% CI: 1.11–2.03, P < 0.01). Conclusions: Various characteristics of OGTTs are associated with different adverse outcomes. A careful reconsideration of GDM with hierarchical and individualized management according to OGTT characteristics is needed.

Is It Time to Change Our Reference Curve for Femur Length? Using the Z-Score to Select the Best Chart in a Chinese Population

Objective To use Z-scores to compare different charts of femur length (FL) applied to our population with the aim of identifying the most appropriate chart. Methods A retrospective study was conducted in Beijing. Fifteen hospitals in Beijing were chosen as clusters using a systemic cluster sampling method, in which 15,194 pregnant women delivered from June 20th to November 30th, 2013. The measurements of FL in the second and third trimester were recorded, as well as the last measurement obtained before delivery. Based on the inclusion and exclusion criteria, we identified FL measurements from 19996 ultrasounds from 7194 patients between 11 and 42 weeks gestation. The FL data were then transformed into Z-scores that were calculated using three series of reference equations obtained from three reports: Leung TN, Pang MW et al (2008); Chitty LS, Altman DG et al (1994); and Papageorghiou AT et al (2014). Each Z-score distribution was presented as the mean and standard deviation (SD). Skewness and kurtosis and were compared with the standard normal distribution using the Kolmogorov-Smirnov test. The histogram of their distributions was superimposed on the non-skewed standard normal curve (mean = 0, SD = 1) to provide a direct visual impression. Finally, the sensitivity and specificity of each reference chart for identifying fetuses <5th or >95th percentile (based on the observed distribution of Z-scores) were calculated. The Youden index was also listed. A scatter diagram with the 5th, 50th, and 95th percentile curves calculated from and superimposed on each reference chart was presented to provide a visual impression. Results The three Z-score distribution curves appeared to be normal, but none of them matched the expected standard normal distribution. In our study, the Papageorghiou reference curve provided the best results, with a sensitivity of 100% for identifying fetuses with measurements < 5th and > 95th percentile, and specificities of 99.9% and 81.5%, respectively. Conclusions It is important to choose an appropriate reference curve when defining what is normal. The Papageorghiou reference curve for FL seems to be the best fit for our population. Perhaps it is time to change our reference curve for femur length.

ARHGEF11 affecting the placental insulin signaling pathway in fetal macrosomia of normal glucose tolerance pregnant women

INTRODUCTION Fetal macrosomia has confirmed be related to multiple labor complications and metabolism syndromes later in life. However, the mechanism of fetal macrosomia in normal glucose tolerance (NGT) and gestational diabetes mellitus (GDM) pregnant women is still obscure. This study aimed to investigate the mechanism of Rho guanine nucleotide exchange factor 11 (ARHGEF11) and the insulin signaling pathway in placenta affecting fetal overgrowth in NGT and GDM pregnant women. METHODS Eighty-nine pregnant women with paired antepartum BMI were recruited and divided into four groups: NGT with normal birth weight (NGT-N, n = 30) or macrosomia (NGT-M, n = 22) and GDM with normal birth weight (GDM-N, n = 22) or macrosomia (GDM-M, n = 15). Placenta tissue was collected to examine the expression of ARHGEF11, ROCK1, the phosphorylation of Tyr612 IRS-1 (p-Y612), Ser307 IRS-1 (p-S307), PI3K, AKT, pAKT, GLUT4 and S6K. RESULTS Gene expression of ARHGEF11, ROCK1, p-S307 and S6K in placenta was significantly increased in the NGT-M group (p < .05). The protein density of ARHGEF11 and ROCK1 was positively correlated with birth weight (p < .001) in the NGT groups. p-Y612, PI3K, pAKT and GLUT4 were significantly decreased in NGT-M, GDM-N and GDM-M group (p < .05). But there was no statistical difference between the two GDM groups. DISCUSSION ARHGRF11 inhibited the insulin signaling pathway in placenta may participated in fetal macrosomia in NGT pregnant women. The insulin signaling pathway was suppressed in GDM placenta, but was not closely related to fetal macrosomia, indicated different mechanism in fetal overgrowth in NGT and GDM pregnant women.